14 posts in this topic

In order to prepare for massive asteroids that could aim for Earth in the future, researchers should ram a spaceship into a real asteroid to see if the space rock would shift course, scientists say.

The proposal, which was presented Wednesday (Dec. 5) at the annual meeting of the American Geophysical Union, would send two spaceships to deflect a small asteroid in a binary (double asteroid) system coming toward Earth in 2022. One spaceship would crash into the asteroid, hopefully deflecting it, while another would observe the collision.

Their goal is to crash into the smaller rock in a binary asteroid system called Didymos that is projected to travel past Earth in 2022.

"This is the biggest problem for planetary defense," said Andrew Cheng, a physicist at the Applied Physics Laboratory at Johns Hopkins, who is proposing the space mission. "There is a risk if we saw an asteroid coming towards us, we wouldn't know if we could do anything about it."

Meteor impacts are rare, but they have devastated Earth several times in the planet's history. For instance, many scientists think a giant meteorite impact caused the massive extinction of the dinosaurs about 65 million years ago.

But while powerful space probes and telescopes can now see asteroids barreling toward Earth from far away, there's no real plan for stopping a giant one from wiping out humanity.

Share this post

Link to post

Share on other sites

Sure, it would work the same way a bug hitting your windshield slows down your car. A spaceship wouldn't have enough mass to make a noticeable difference to a huge rock hurling through space at incredible speed. This idea is just silly.

Share this post

Link to post

Share on other sites

[quote name='TRC' timestamp='1355011491' post='595378110']
Sure, it would work the same way a bug hitting your windshield slows down your car. A spaceship wouldn't have enough mass to make a noticeable difference to a huge rock hurling through space at incredible speed. This idea is just silly.
[/quote]

You are making wrong assumptions though. On Earth we are bound to the surface by gravity and thus a car traveling at xxx speed being hit by a bug flying at xxx won't affect the speed of the vehicle much (it does actually, but it's an extremely small amount). In space, there is no gravity and as you (should) know, objects in space just keep going in whatever direction they are going, unless something else acts upon it. So a spacecraft traveling at a high velocity in space smashing into a huge asteroid (or small one, doesn't matter) does have a small effect on the object it hits. We are talking about again, really small amounts here. But you only have to change it's orbit by a small amount for it to bypass a direct collision with Earth.

They are thinking the same sorts of ideas with using spacecraft with just it's own gravity (again, however small it may be), to pull and/or push any approaching object into a more agreeable orbit. The laser/microwave thought is that vaporizing surface volatiles will give off enough exhaust particles to change the orbit path of the object.

Also, while we are only looking at a very small percentage of the sky with NASA and other space agency telescopes, many people around the world are looking through their own telescopes, and any object big enough to be a threat would still be seen pretty far out there. It would take a very fast object in a blind spot so to speak, to hit us literally without warning. That's not to say that can't happen, of course it can. But the likelihood is pretty tiny I'd say.

Share this post

Link to post

Share on other sites

If there's a rock heading to earth, I'm just going to assume humanity's number was up, then travel to the crash site so I can be among the first to die in the glorious inferno. All the better if I could be flying a plane above the crash site, finally put my pilot's license to good use.

Share this post

Link to post

Share on other sites

[quote name='siah1214' timestamp='1355012589' post='595378142']
If there's a rock heading to earth, I'm just going to assume humanity's number was up, then travel to the crash site so I can be among the first to die in the glorious inferno. All the better if I could be flying a plane above the crash site, finally put my pilot's license to good use.
[/quote]

Go out in a Blaze of glory if you can get the meteor to hit your plane before hitting Earth. I'd like to book a ticket please. Can we go out to "Rock you like a Hurricane"?

Share this post

Link to post

Share on other sites

[quote name='McKay' timestamp='1355011200' post='595378100']
The biggest risk to planetary defence is that we only actively scan 3% of the sky. A World ending meteor could hit us any second and we'd never know until the second before it hit.
[/quote]

Not entirely true. the problem is that earth is a sphere and so stuff can hit us from any direction. of course being a sphere that means the further away you get the larger the surface to scan is. and since space is so unimaginably large and even large planet killer meteorites are so small, we simply can't see them coming. unless we point a scope like the hubble, directly at it at max magnification, and even then we can only see it when it extremely close, relatively speaking. so we scan the whole sky, just at to low res to see anything, and even the few percent we actively scan at high magnification, we'd be extremely lucky to find something there before it's to late.

Share this post

Link to post

Share on other sites

[quote name='LOC' timestamp='1355012411' post='595378138']
You are making wrong assumptions though. On Earth we are bound to the surface by gravity and thus a car traveling at xxx speed being hit by a bug flying at xxx won't affect the speed of the vehicle much (it does actually, but it's an extremely small amount). In space, there is no gravity and as you (should) know, objects in space just keep going in whatever direction they are going, unless something else acts upon it. So a spacecraft traveling at a high velocity in space smashing into a huge asteroid (or small one, doesn't matter) does have a small effect on the object it hits. We are talking about again, really small amounts here. But you only have to change it's orbit by a small amount for it to bypass a direct collision with Earth.

They are thinking the same sorts of ideas with using spacecraft with just it's own gravity (again, however small it may be), to pull and/or push any approaching object into a more agreeable orbit. The laser/microwave thought is that vaporizing surface volatiles will give off enough exhaust particles to change the orbit path of the object.

Also, while we are only looking at a very small percentage of the sky with NASA and other space agency telescopes, many people around the world are looking through their own telescopes, and any object big enough to be a threat would still be seen pretty far out there. It would take a very fast object in a blind spot so to speak, to hit us literally without warning. That's not to say that can't happen, of course it can. But the likelihood is pretty tiny I'd say.
[/quote]

more importantly IF we detect it early enough to be of any use, even if the impacter can only deflect the course by 0.0001 degrees. Over the huge distance before it gets to earth, that's infinitesimal change in course is enough to not only make it miss earth, but not even be close. so it takes very little to do it. of course of they calculate it wrong, they could make it hit earth not miss it

most people think we can just shoot nukes at them and be fine, not realizing that int he vacuum of space, an kinetic impacter would be far more useful than a burst of radiation.

Share this post

Link to post

Share on other sites

[quote name='McKay' timestamp='1355011200' post='595378100']
The biggest risk to planetary defence is that we only actively scan 3% of the sky. A World ending meteor could hit us any second and we'd never know until the second before it hit.
[/quote]

Share this post

Link to post

Share on other sites

Nope, won't work, there are physics experts that work out this type of stuff for a living, some of the best brains on the planet DO work for NASA, we'll need Bruce Willis to go up with 2 teams, partly lose one on apporach, land in the wrong grid, lost more members to astro storms, await for the presumed dead second team to arrive, drill a hole, drop a nuke, realise it's remote and timer aren't working, stay behind, and then as the only team surviving escapes, blow the living sh*t out of it, leaving Ben Affleck free to marry Liv Tyler